Sealed high frequency transformer



Get. 17, 1939. R. l. CQLE ET AL 2,176,064 5mm) HIGH FREQUENCY TRANSFORMER Fiied May 19, 1937 I; Illlfl.

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Patented Oct. 17, 1939 UNITED STATES PATENT OFFICE SEALED HIGH TRANSFORMER Application May 19, 1937, Serial No.'143,53'l Claims. (Cl. 250-16) (Granted under the act of March 3, 1883,

mended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to us of any royalty thereon.

This invention relates to improvements in high frequency transformers and proposes a unique method of mounting the elements of such a transformer in sealed and fluid-tight assembly and/or in a vacuum.

The invention contemplates a system in which the inductance and capacity elements, for example, are sealed in an evacuated container or a container in which may be introduced a gas or gases of low moisture content, and in any desired proportion.

The invention further contemplates a transformer comprising separate components or sealed units in each of which the transformer elements are associated in operative relation and in fluid-tight assembly in the respective containers. I

An important object of the invention is to effect tuning control of the elements, more particularly of the inductance elements, and externally of the sealed container, vacuum sealed or otherwise, while maintaining undisturbed the sealed or fluid-tight condition of the containers.

In addition to the idea of tuning control of the resonant frequency, means is also provided to vary and control the mutual coupling of the inductance elements without disturbing the fluid-tight state of the containers.

The idea of sealing the tuning elements individually in separate containers affords greatly improved operation under changing climatic conditions, and with greater efliciency. It is desired to stress the advantage of frequency control external to the container itself on the one hand, and the principle of variable coupling with each tuned circuit sealed in individual containers on the other hand, and while maintaining the sealed state unimpaired.

Thus it will be seenthat an important concept of the invention is to combine a coil and a condenser in a sealed container, and provide means whereby tuning may be accomplished externally of the container itself and by an instrumentality not mechanically connected to the container.

Other objects and advantages will appear as the description proceeds. The invention will now be described in detail with reference to the accompanying drawing, in which:

Fig; 1 is a sectional diagrammatic view of a amplifier in circuit relation transformer embodying the features of the invention;

Fig. 2 is a schematic diagram showing the elements of the invention as a transformerto electron tubes; and V Fig. 3 is a view in longitudinal section of a physical embodiment of the invention.

Referring to Fig. 1 of the drawing, the transformer construction shown comprises two completely sealed containers I and 2, which may be formed of glass, ceramic or other suitable material capable of being made fluid-tight. These containers as contemplated by the present invention may be evacuated, that is they may be vacuum sealed; or they may be evacuated and a gas or gases of low-moisture content may be introduced in any proportion or amount desired. In the embodiments here shown each container is formed so as to encompass an annular chamber 3, due to the centrally located tubular passages 4-4 which constitute cylindrical passage-ways open at each end. These unit containers are mounted coaxially as shown and disposed in each annular chamber are coils or inductances 5-5 35 ways as a core mounting. In the present embodiment, it will be understood that an interstage coupling transformer is shown by way of example which comprises frequency tuning or control elements 44' in the respective components..of the said transformer, and provided respectively withadjusting screws 8-8. The tuning element in the nature of a core of magnetic material. It will be understood that the transformer here shown by way of example, is an interstage coupling device which conventionally employs inductance and capacity elements, the coils 5 and 5' in this instance constituting the primary and secondary of such a transformer, and the tuning cores 44' being formed of ferro-magnetic material. The adjusting screws 8-8 permit independent adjustment of these tuning elements 4-4.

In order to vary and control the mutual magnetic coupling between the respective coils a pair or group of adjusting screws 89 are provided to operate with container I and a similar pair or group of adjusting screws ill-I0 afford means for corresponding adjustment of container 2. These screws are threaded through sleeves as at lL-ll' and lZ-II'. A frameas "functions as a mounting and support for the transformer structure. It will be understood that the indepresent instance is in the 5 pendent mutual coupling adjustment may be made first, while the tuning. adjustment by means of the respective cores 4-4 may then be made, or the sequence of adjustment may be in reverse order.

In general the circuit relationship of the elements of such a transformer in a circuit system will be clear by reference to the schematic showing of Fig. 2, when considered in conjunction withthe structural diagram of Fig. 1. In Fig. 2 the numerals I4 and II designate three element electron tubes to the end that-the input and output connections may be understood. The arrangement is conventional and description in detail seems unnecessary.

Again it is desired to emphasize the unique and novel idea of combining a coil and condenser in a sealed container, fluid tight by construction and definition, and vacuum sealed or otherwise as previously pointed out. The advantages of such a transformer construction are freedom from humidity and barometric pressure influences on the characteristics whereby undesired changes in frequency or other electrical relationships are avoided after adjustment. These constitute material advantages over previously known structures in the art.

Fig. 3 is intended to illustrate one actual physical and practical embodiment of such a transformer structure.

Changes, modifications and alternative arrangements are contemplated within the scope of the invention and as defined by the appended claims.

We claim:

1. In a transformer system, separate resonant circuits each comprising variable inductance and fixed capacity elements, said inductance elements being coupled in electro-magnetic relationship; means including a sealed container for mounting each inductance and capacity element in fluid-tight assembly; a ferro-magnetic core mcvably associated with each inductance element and externally of each of said containers; and means to eifect relative movement of cores and inductance elements for tuning said circuits while maintaining the fluid-tight condition of said containers undisturbed.

2. In a device of the character described, a system of inductance and capacity elements with the inductance elements coupled in electro-magnetic relation; means including a sealed container for mounting each inductance and capacity in fluid-tight assembly and as a group; means for tuning the system to resonance externally of each of said containers, said means including iron cores movable with respect to each inductance; and means to vary and control the mutual coupling of the said groups of elements and independently of the movement of the cores. while maintaining said containers in fluid-tight condition.

3. In an electrical transformer system comprising separate components, each component including a variable inductor and fixed capacitor connected in circuit parallel, and said inductors being coupled 'in electromagnetic relation with one another; means including evacuated containers for separately mounting said components in a vacuum; and means including iron cores movably associated with said inductors for tuning'said system to resonance withoutdisturbing the state of vacuum in said containers.

4. In an electrical transformer comprising separate assemblies, each assembly including variable inductance and fixed capacity elements, said inductance elements being mutually coupled with one another; means comprising an evacuated container for mounting each inductance and capacity element together in a vacuum, said elements being connected in circuit parallel; a ferro-magnetic core adjustably associated with each inductance and externally of said container;

means for adjusting each of said cores in relation to each inductance to effect tuning control of each circuit; and means for changing the space relation of said containers to vary and control the mutual electro-magnetic coupling of said inductances and without disturbing the state of vacuum in the containers.

5. In an electrical transformer, a system of variable inductors mutually coupled in electromagnetic relationship and fixed capacity elements in circuit parallel with said inductors as a part of said system; means including evacuated containers for mounting said inductors and capacity elements in a vacuum; means including cores of ferro-magnetic material adjustable with respect to said inductors to effect tuning control of the system without disturbing the state of vacuum in said containers; and means acting independently of said tuning control to vary and control the mutual coupling of the inductors of said containers with relation to each other while maintaining the state of vacuum undisturbed.

6. In an amplifier system, inductance elements mutually coupled in electro-magnetic relation, and a fixed capacity element in circuit parallel with each inductance; means including separate evacuated containers for mounting each assembly of inductance and capacity elements in vacuo; a tuning device comprising a ferro-magnetic core movable in relation to each inductance and disposed externally of each container to effect tuning control of the inductance in each container; and means for changing the mutual coupling of the system by external movement of said containers and without disturbing the state of vacuum.

7. In a transformer system, comprising inductors mutually coupled in electro-magnetic relationship; a fixed capacitorconnected in circuit parallel with each inductor; means including sealed containers for mounting said inductors and capacitors in fluid-tight assembly; tuning means to vary and control the inductance externally of said containers; and means operative independently of said tuning means for changing the mutual coupling of the inductors while maintaining the sealed and fluid-tight condition of the containers undisturbed.

8. In a transformer system, comprising variable inductance and fixed capacity elements, said inductance elements being coupled in operative electrical relationship; means for mounting an inductance and a capacity element in circuit parallel and in fluid-tight assembly, said means including containers in each of which said elements are sealed together; means comprising fe'rro-magnetic cores operable externally of said containers to effect tuning control of said inductance elements in each of the containers; and means for varying the mutual coupling of said inductance elements independently of said tuning control while maintaining the fluid-tight condition of the containers undisturbed.

9. In a transformer system comprising variable inductance and fixed capacitance elements operatively associated in circuit parallel, said inductance elements being mutually coupled; 75

means including sealed containers for coupling each inductance element and each capacitance element together in groups, said containers forming fluid-tight mountings for each of said groups; means comprising a magnetic core adjustable in relation to each inductance and operable externally of each container to eflect tuning control of said inductance elements; and means for varying the-said mutual coupling of the inductance elements of the respective containers while maintaining undisturbed the fluid-tight condition of the containers.

10. In a transformer system comprising operatively associated resonant circuits, each circuit including a variable inductor and flxed capacitor connected in circuit parallel; means including sealed containers for mounting each of said circuits in fluid-tight assembly; means to eflect tuning control of each of said circuits, said means including a term-magnetic core concentric with and adjustable externally of each container in relation to each of said inductors; and means for changing the spacing between said containers to vary the mutual inductive coupling oi said circuits and independently of the position 0! said cores while maintaining undisturbed the fluidtlght condition of said containers.

11. In a device of the character described, comprising variable inductors and fixed capacitors connected in parallel therewith, each inductor and capacitor comprising a separate circuit and the inductors being coupled in-mutually inductive relationship; ferro-magnetic cores concentric with and capable of movement in relation to each inductor; means including sealed containers for mounting said inductors and capacitors in fluidtight assembly; means to effect tuning control oi the system externally 01' each of said containers by movement of said cores with respect to the inductors; and means to vary and control the mutual inductive coupling 01' said separate circuits, and independently of the movement oithe cores, while maintaining the fluid-tight state of the respective containers.

12. In an electrical transformer system, separate assemblies 0! variable inductance elements mutually coupled in inductive relationship and including fixed capacity elements in parallel with said inductors as a part of said system: ferromagnetic cores concentric with said inductances; means including evacuated containers for moimtin; said elements in avacuum tothe exclusion of said cores; means to change the space relation between the said cores and inductance elements to eflect tuning control 01' the system without disturbing the state 01' vacuum in said containers; and means to vary and control the mutual inductive coupling of the inductance elements of said containers with relation to each other while maintaining the state of vacuum undisturbed.

13. In a transformer system, comprising coils mutually coupled in electrical relationship; fixed capacitors connected in circuit parallel with each coil; iron cores concentric with each coil and adiustable therewith for inductance control; sealed containers formed of dielectric material for mounting said coils and capacitors to the exclusion of the iron cores in fluid-tight assemblies; means for'adjusting said cores to vary and control the inductance of said coils and externally 01' said containers; and means for changing the mutual coupling of the coils.

14. In a transiormer system comprising separate mutually coupled variable inductors and fixed capacitors connected in circuit parallel; means including sealed containers oi dielectric material for housing each inductor and capacitor as a group, said containers forming fluid-tight mountings for each of said groups; means comprising an iron core operable externally 0! each container in variable relation to the said inductors for tuning the circuits to resonance; and means for varying the mutual coupling of the inductance elements oi! the respective containers.

15. In a transformer system comprising coils mutually coupled in inductive relation; a fixed capacitor connected in circuit parallel with each coil; iron cores concentric with each coil and adjustable therewith tor inductance control; sealed containers of dielectric material for mounting each of said parallel circuits in fluid-tight assembly and to the exclusion of the iron cores, each container being i'ormed to encompass an open-ended tubular bore to permit movable ad- Justment therein 0! each core; means for adlusting said cores to vary and control the inductance of said coils without disturbing the fluidtight condition 01 the containers; and means for moving the containers to control the mutual inductive coupling of said coils in relation to one another.

RALPH I COLE.

non n. ws'rson. 

